v3.21.2
Trading Cash Instruments - Cash Instruments, Level 3 Rollforward (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Trading Cash Instruments Assets [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance $ 1,373 $ 1,234 $ 1,237 $ 1,242
Net realized gains / (losses) 23 17 42 68
Net unrealized gains / (losses) 10 (40) 16 (190)
Purchases 275 306 647 609
Sales (284) (212) (401) (320)
Settlements (100) (42) (208) (183)
Transfers into level 3 148 695 181 761
Transfers out of level 3 (141) (154) (210) (183)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 1,304 1,804 1,304 1,804
Trading Cash Instruments Assets [Member] | Loans and Securities Backed by Commercial Real Estate [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 115 130 203 191
Net realized gains / (losses) 2 2 5 13
Net unrealized gains / (losses) (3) (9) (9) (33)
Purchases 10 20 7 79
Sales (13)   (37) (13)
Settlements (5) (6) (13) (57)
Transfers into level 3 5 294 19 255
Transfers out of level 3 (15) (1) (79) (5)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 96 430 96 430
Trading Cash Instruments Assets [Member] | Loans and Securities Backed by Residential Real Estate [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 204 251 131 231
Net realized gains / (losses) 4 3 8 7
Net unrealized gains / (losses) 9 2 10 11
Purchases 4 5 21 41
Sales (76) (89) (42) (68)
Settlements (7) (7) (9) (24)
Transfers into level 3 12 181 31 178
Transfers out of level 3 (20) (39) (20) (69)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 130 307 130 307
Trading Cash Instruments Assets [Member] | Corporate debt instruments [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 918 719 797 692
Net realized gains / (losses) 12 9 26 35
Net unrealized gains / (losses) 3 (23) 20 (137)
Purchases 215 140 554 303
Sales (164) (93) (287) (175)
Settlements (77) (20) (151) (85)
Transfers into level 3 65 138 35 235
Transfers out of level 3 (81) (106) (103) (104)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 891 764 891 764
Trading Cash Instruments Assets [Member] | Other Cash Instruments [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 136 134 106 128
Net realized gains / (losses) 5 3 3 13
Net unrealized gains / (losses) 1 (10) (5) (31)
Purchases 46 141 65 186
Sales (31) (30) (35) (64)
Settlements (11) (9) (35) (17)
Transfers into level 3 66 82 96 93
Transfers out of level 3 (25) (8) (8) (5)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 187 303 187 303
Trading Cash Instruments Liabilities [Member]        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Beginning Balance (106) (194) (80) (273)
Net realized gains / (losses) 2 (1) 4  
Net unrealized gains / (losses) (2) 15   105
Purchases 35 21 28 40
Sales (27) (15) (39) (22)
Settlements 20 5 10 1
Transfers into level 3 (5) (8) (4) (10)
Transfers out of level 3 5 21 3 3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value, Ending Balance $ (78) $ (156) $ (78) $ (156)